a. Field of the Invention
The present invention relates to warheads and more particularly to armor penetrating controlled fragmentation warheads.
B. Description of the Prior Art
Conventional bombs and warheads detonate in a manner that produces fragments of inadequate energy at impact to perforate armor plate of the thickness employed in armored vehicles and tanks. These devices typically distribute their energy into broad patterns with fragments of irregular size and shape. Too few fragments with inadequate kinetic energy are delivered to the target to be effective in defeating the target. Other means of defeating armor that have sufficient energy require great delivery accuracy or a large number of devices to be effective. Two such devices are artillery projectiles and shaped charges. In addition, other prior art methods of explosive detonation have been tried in combination with different size and shape fragments. Only limited success has been achieved because of fragment divergence into too broad a pattern with again too few fragments placed on the target to be effective.
Prior art warheads are based on the presumption that all warheads will explode with a random fragment dispersal. Extensive research in development of the present invention disclosed that fragments of larger mass and of nearly identical shape will disperse in a predictable pattern based on their orientation in the warhead and the configuration and method of detonation of the explosive charge in the warhead.
Based on these findings, the present invention includes several novel features over the teaching of the prior art that make possible the solution of the problem. These are:
1. Explosive tamping -- The presence of the main charge high explosive around the ends of the fragment layer maintains ejection of the fragments in a narrow beam when detonated using existing simultaneous or near simultaneous initiation technology. The explosive tamping provides a way to control the fragment beam from the warhead.
2. Fragmentation arrangement -- Orientation of the rows of fragments such that no two rows are lined up with each other provides even diametral spacing of the fragments over the area of interest when the warhead is detonated. This improves the likelihood of hitting and defeating a target in the area of interest for the warhead. Since there is a direct relationship between the fragment arrangement in the warhead to the fragment pattern at the target, the warhead can be constructed to produce the optimum pattern for a particular target.
3. Mild steel fragment material -- Existing armor penetration theory maintains that in order to penetrate a material, the material of the penetrator must be as hard or harder than the target material. The present invention has used unhardened mild steel fragments that in conjunction with the other features have allowed the armor penetrating fragmentation warhead disclosed herein to perforate more than 4 inches of rolled homogeneous armor in actual demonstration tests.
4. Keystoned preformed fragments -- By preforming the fragments, the correct shape and mass to perforate over 4 inches of armor can be constructed to be delivered to the target. Keystoning requires that the two sides of each fragment be inclined toward the center of the warhead so that when assembled in cylindrical fashion, the sides of the fragments will be in total contact with each other. Keystoning of the fragments insures the integrity of the preformed fragments during acceleration by the shock wave from the high explosive detonation of the warhead. Without keystoning the fragments may or may not be ejected from the warhead with the desired mass. Fragment breakup occurs and the predetermined fragment size and shape is not delivered to the target.
Therefore, an object of the present invention is to provide a controlled fragmentation warhead which provides for maximum delivery of kinetic energy to the target.
It is a further object of the present invention to provide a fragmentation warhead with a controlled fragmentation beam.
It is a still further object of the present invention to provide a fragmentation warhead with a controlled fragment delivery pattern.
It is another object of the present invention to provide an armor penetrating controlled fragmentation warhead capable of employing mild steel fragments.
It is yet another object of the present invention to provide an armor penetrating controlled fragmentation warhead with the objectives hereinbefore described which will penetrate 4 inches of armor plate yet which is easily produced with a minimum of specialized equipment and which can be packaged in and delivered by conventional devices.
Other objects and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.